This abacus is heavily adorned with engravings in gold and platinum. The metal bars that hold the beads are made of pure electrum, and the beads themselves are small carved gems. The abacus immediately appears extremely valuable, yet without any magical means to identify it or the proper attunement, no properties are revealed within. The beads glow in various colours that light up when you use them to calculate. 

The abacus has strange properties once attuned to it, and using it now seems to alter what you see in front of you. You gain the cantrip Minor Illusion at will while using it, and if you fiddle with it, it can project a memory of your choosing that you have, or make a makeshift projection of a tale you tell onto a flat 20x20ft surface visible to all people. This use expends one charge. 

Additionally you may also expend 1 charge to cast the spell Major Image or Hypnotic Pattern, or 3 charges to cast Hallucinatory Terrain. The item holds up to 5 charges, recharging 1d4+1 charges every dawn. The item uses its own spell difficulty (DC 16) and holds concentration of the spell for you as long as you are holding it. If you would have to make a constitution saving throw to maintain concentration on a spell cast by the Abacus, use your own stats to do so. The concentration this item holds does not count against your own maximum of concentration spells at once. 

If the item is attuned to by a creature with eidetic or photographic memory, or the Keen Mind feat, the projection of the memory from this item's first property is crystal clear, as if you were watching it in real time, with all attention to detail and recalling and showing any and all details the creature saw, even if the creature itself cannot remember the detail to its full extent, as their mind captured it, despite it not being of any importance; i.e. if a creature was watching a fight happen and in their line of sight another creature passed through its field of vision inadvertedly, that creature appears in the projection, despite the recalling creature's indifference towards that thing. 

Notes: spellcaster